Soil Ecosystem Services Research Articles

Assessing and mapping changes in soil ecosystem services and soil threats in agroecosystems through scenario-based approaches - A systematic review.

Scenario analysis plays a central role in estimating how global changes affect the relationships linking ecosystem conditions and functioning to human needs. This is particularly true for agroecosystems, which are pivotal to ensure sustainable land planning, ecological management and food security strategies. Soils are key providers of multiple ecosystem services (ES) in agroecosystems but they are very sensitive to global drivers such as changes in climate, land use and cover. How agroecosystems should achieve sustainability, through optimizing soil capacity to supply ES while limiting the occurrence of threats, is a priority of EU policy agendas. Nevertheless, there is currently a lack of a comprehensive framework of scenario-based approaches to assess changes in soil ES (SES) and soil threats (ST). As a part of the project SERENA funded by the European Joint Program on Agricultural Soil Management, this study aims to: i) understand how drivers of global change are commonly studied in the scientific literature; ii) identify how some SES and ST are assessed in scenario-based approaches; iii) provide a preliminary discussion on how soil properties are represented in these approaches. Through a systematic review of 230 published articles related to seven SES and ten ST, this study highlights that not all SES and ST are considered with the same frequency and geographic distribution in scenario-based approaches. Despite a great methodological variability in the assessment and mapping of SES and ST, dominant methodological trends can be identified. SES are mapped more frequently than ST and, specific SES appear more disposed to spatially explicit assessments than others. Due to its novelty and complexity, research on this topic is limited to a small subset of ST or SES and projections of the combined impacts of climate, land use and management changes on multiple ST and SES should be a scientific priority to help policy makers.

Improving the spatial prediction of topsoil properties in a typical grazing area using multi-season PlanetScope spectral covariates and data mining techniques

Understanding the spatial distribution of topsoil properties in grassland ecosystems is essential for improving soil ecosystem services, quality, and erosion resilience. The availability of free, high-resolution satellite imagery and advanced data mining techniques offers new opportunities for efficient soil property assessment. This study aimed to evaluate the potential utility of multi-season PlanetScope imagery to predict soil organic carbon (SOC), pH, and calcium carbonate (CaCO3). Using random sampling, 121 topsoil samples (0–30 cm depth) were collected with an auger across grasslands, bare soil, and eroded areas within a typical grazing land use. Three data mining techniques: random forest (RF), extreme gradient boosting (XGB), and support vector machines (SVM), were applied and evaluated using a 10-fold cross-validation. The results indicated that multi-season spectral covariates considerably improved the accuracy of the target soil properties compared to single-season imagery. SVM was the most effective algorithm for predicting SOC, achieving a root mean square error (RMSE) of 0.52%, mean absolute error (MAE) of 0.24%, and R² of 0.92. RF was the best-performing algorithm for predicting soil pH (RMSE = 0.22, MAE = 0.17, and R² = 0.97) and CaCO3 (RMSE = 0.55%, MAE = 0.42%, and R² = 0.96). While XGB failed to capture the variability in soil pH, the other models generated interpretable maps that accurately represented the distribution of soil properties across different land cover categories. The green-red vegetation index (GRVI) was the most critical covariate for predicting SOC, while elevation and the topographic wetness index (TWI) were key predictors for soil pH and CaCO3, respectively. This study underscores the potential of multi-season PlanetScope imagery for accurately predicting soil properties and recommends conducting similar studies in diverse geographical settings to validate these findings and develop more generalizable models.

Quantification of Soil–Water Erosion Using the RUSLE Method in the Mékrou Watershed (Middle Niger River)

Despite nearly a century of research on water-related issues, water erosion remains one of the greatest threats to soil health and soil ecosystem services around the world. Yet, to date, data on water erosion needed to develop mitigation strategies are scarce, especially in the Sahelian regions. The current study therefore sets out to estimate annual soil losses caused by water erosion and to analyze trends over the period of 1981–2020 in the Mékrou watershed, located in the Middle Niger river sub-basin in West Africa. The Revised Universal Soil Loss Equation, remote sensing, and the Geographic Information System (GIS) were deployed in this study. Several types of data were used, including rainfall data, sourced from meteorological stations and reanalysis datasets, which capture the temporal variability of erosive forces. Soil properties, including texture and organic matter content, were derived from FAO global soil databases to assess soil erodibility. High-resolution digital elevation models (30 m) provided detailed topographic information, crucial for calculating slope length and steepness factors. Land use and land cover data were extracted from satellite imagery, enabling the analysis of vegetation cover and anthropogenic impacts over four decades. By integrating and treating these data, this study reveals that the estimated average annual amount of water erosion in the Mékrou watershed is 6.49 t/ha/yr over 1981–2020. The dynamics of the ten-year average are highly variable, with a minimum of 3.45 t/ha/yr between 1981 and 1990, and a maximum of 8.50 t/ha/yr between 1991 and 2000. Even though these average soil losses in the Mékrou basin are below the tolerable threshold of 10 t/ha/yr, mitigation actions are needed for prevention. In addition, the spatial dynamics of water erosion are noticeably heterogeneous. The study reveals that 72.7% of the surface area of the Mékrou watershed is subject to slight water erosion below the threshold, compared with 27.3%, particularly in the mountainous south-western part, which is subject to intense erosion above the threshold. This research is the first study of soil erosion quantification with the RUSLE method and GIS in the Mékrou watershed, and fills a critical knowledge gap of the water erosion in this watershed, providing insights into erosion dynamics and supporting future sustainable land management strategies in vulnerable Sahelian landscapes.

Perennial Grasses on Stony Sandy Loam Arenosol: Summary of Results of Long-Term Experiment in Northern Europe Region (1995-2024).

Grasses can sustain soil functions despite nutrient depletion, which can have serious consequences for soil processes and ecosystem services. This paper summarizes the results of the long-term experiment (1995-2024) carried out in Arenosol within a temperate climate zone, focusing on the productivity of natural and managed grasslands; their succession changes over time, and so do the effects on soil chemical properties, and soil organic carbon (SOC) sequestration. The results indicated that two land uses-abandoned land (AL) and grassland fertilized with mineral fertilizers (MGf)-can be effectively applied to prevent Arenosol soil degradation. SOC accumulation occurs more rapidly in AL soils, and their chemical properties show less change over time. The ability of grasses to sequester SOC is better reflected by SOC stocks across the Ah horizon, where thickness varies over long-term grassland use. Significant changes in soil properties were observed more than 20 years after converting arable to herbaceous land use. While MGf has the highest biomass productivity, the use of fertilizers leads to soil acidification. The biomass productivity of AL and MGf increased with longer grassland use; however, in MG, productivity decreased without fertilizers, reaching AL's productivity levels after 20 years. As the age of AL increased, plant biodiversity decreased, and drought-resistant plants began to spread.

Forest management interventions affect the trade-offs of multiple vegetation and soil ecosystem services in walnut forests in the Taihang Mountains, China

Forest management interventions affect the trade-offs of multiple vegetation and soil ecosystem services in walnut forests in the Taihang Mountains, China

Native versus non-native Prosopis woody species: Which fertilize the soil better?

Abstract This study assessed differences in the physical, chemical, and microbial properties of soils under trees of the native species Prosopis cineraria and the invasive species Prosopis juliflora trees, focusing on implications for ecosystem management and restoration. At the start of the growing season, 30 trees of each species with a trunk diameter of 15–30 cm were randomly selected. Soil samples were taken from the top 20 cm of soil profiles east of each tree, under the tree crowns and from control plots in open areas. Three soil samples per site were pooled for chemical and microbial analysis. Soil moisture was highest under P. cineraria (14.64 ± 0.3) and lowest in control plots (9.04 ± 0.65). Soil pH was highest in control soils (7.91 ± 0.09), slightly lower under P. cineraria (7.77 ± 0.06), and lowest under P. juliflora (7.49 ± 0.0). Electrical conductivity, soil salinity was highest under P. juliflora (2.25 ± 0.12). Microbial activity indicators (basal respiration and microbial biomass carbon) were greater under P. cineraria than under P. juliflora trees. Native P. cineraria trees enhance soil conditions, benefiting ecosystem management. In contrast, invasive P. juliflora trees raise soil salinity, threatening soil quality, biodiversity, and ecosystem services in the Sahara-Sahel region. Managing the spread of P. juliflora is crucial to maintaining ecosystem functions.

Perennial flower strips in agricultural landscapes strongly promote earthworm populations

The loss of soil biodiversity through agricultural intensification is a major contributor to the collapse of ecosystem services. Despite their wide application to promote biodiversity, the impact of flower strips on soil organisms is largely unknown. Here, we studied the effects of perennial flower strips on earthworm communities at 46 sites with paired croplands and perennial flower strips. Earthworm population densities in flower strips were on average 231% greater than in adjacent croplands. Flower strips can enable the establishment of anecic and epigeic populations at sites at which they are absent in croplands. Furthermore, flower strips likely serve as a habitat for the reproduction of endogeic earthworms. We expect that the promotion of earthworms through flower strips improves soil functions and benefits higher trophic taxa. We propose that optimized seed mixtures, improved spatial configuration, and establishment of temporal continuity of flower strips can further promote soil ecosystem services.

Exploring the significance of different amendments to improve phytoremediation efficiency: focus on soil ecosystem services.

Phytoremediation is recognized as an environmentally, economically and socially efficient phytotechnology for the reclamation of polluted soils. To improve its efficiency, several strategies can be used including the optimization of agronomic practices, selection of high-performance plant species but also the application of amendments. Despite evidences of the benefits provided by different types of amendments on pollution control through several phytoremediation pathways, their contribution to other soil ecosystem functions supporting different ecosystem services remains sparsely documented. This current review aims at (i) updating the state of the art about the contribution of organic, mineral and microbial amendments in improving phytostabilization, phytoextractionof inorganic and phytodegradation oforganic pollutants and (ii) reviewing their potential beneficial effects on soil microbiota, nutrient cycling, plant growth and carbon sequestration. We found that the benefits of amendment application during phytoremediation go beyond limiting the dispersion of pollutants as they enable a more rapid recovery of soil functions leading to wider environmental, social and economic gains. Effects of amendments on plant growth are amendment-specific, and their effect on carbon balance needs more investigation. We also pointed out some research questions that should be investigated to improve amendment-assisted phytoremediation strategies and discussed some perspectives to help phytomanagement projects to improve their economic sustainability.

Evaluation of the Impact of Plant Protection Products (PPPs) on Non-Target Soil Organisms in the Olive Orchard: Drone (Aerial) Spraying vs. Tractor (Ground) Spraying

Policies aimed at reducing plant protection products (PPPs) are part of the UN’s 2030 Agenda for Sustainable Development. Sustainable management of PPPs is crucial for soil health, biodiversity, and ecosystem services, including food provision. While PPPs can control pests and enhance agricultural yields, they also pose environmental and health risks by contaminating water, soil, and non-target organisms through airborne drift. Investigating innovative and more sustainable distribution methods can support sustainability goals. This study aimed to evaluate the potential impact of the pesticide Spintor® Fly on non-target soil organisms in olive orchards comparing two spraying methods: a traditional Casotti® pump mounted on a tractor and an innovative Unmanned Aerial Vehicle (UAV) developed for the project. The study was conducted in 2021 in an organic olive orchard, which was divided into two plots: a Casotti-treated plot (CAS) and a drone-treated plot (DRO). A strip of uncultivated land at the edge of the orchard was used as a (non-treated) control plot (CAP). The impact on native soil microarthropod communities was assessed using the arthropod-based Soil Biological Quality Index (QBS-ar) and Bait Lamina Test (BLT). Soil samples were collected for earthworm avoidance tests and soil chemical–physical analysis. The results obtained with QBS-ar and BLT indicated no significant differences between DRO and CAS, in both sampling periods (pre- and post-treatment). However, DRO generally exhibited slightly better performance than CAS. The avoidance behaviour was confirmed for both CAS and DRO, although it was lower for the latter. Overall, drone aerial spray performed slightly better, suggesting a potentially lower impact on soil communities. Our results provide initial clues for the sustainable use of drones in agriculture with no increased risks for soil health compared to traditional methods. Further long-term studies should be conducted to validate these findings and possibly confirm the long-term benefits of drone applications compared to traditional methods.

Soil Health and Ecosystem Services in Mangrove Forests: A Global Overview

This study analyzed the role of soil health (SH) and ecosystem services (ESs) in global mangrove research articles from 1958 to 2024. The SH approach is vital for evaluating mangroves’ ability to provide ES. However, most studies made no reference to these topics, an important gap that must be addressed. We performed a systematic literature review of the Scopus database using the following prompts: Level 1: “mangrove*” and “soil” or “sediment”; Level 2: “mangrove*” and “soil health” or “soil quality”; and Level 3: “mangrove*” and “soil health” or “soil quality” and “ecosystem service*” or “ecologic* service*”. A total of 8289 scientific articles were published that explored mangrove soils or sediments, of which 321 included a discussion of SH, and 39 discussed SH and ES. There is a historical preference for the term “sediment” in marine sciences. Carbon is the most studied topic. Six of the fifteen most productive countries are also among the fifteen with the largest mangrove areas. There is a scientific gap regarding studies that link mangrove soil studies with SH and ES. We recommend the development of a soil health index fully adapted to mangroves, considering their physical and geochemical dynamics, climate conditions, and anthropic relevance.

Effects of Organic Amendments on Earthworm Population in Sugarcane Plant Ratoon System under Different Planting Methods

This research aimed to study the effect of organic sources under different planting methods on the population of earthworm in sugarcane plantation for plant and ratoon crop. The experiment was conducted at Regional Agricultural Research station, Anakapalle (Andhra Pradesh) on sandy loan soils under split split plot design with different planting methods, soil health management practices and nutrient levels. The main plots consisted of three planting methods M1: conventional planting, M2: paired row planting, M3: dual row planting along with four organic amendments as sub plots (Control, trash mulching + biodecomposer (A & B), green manuring with sunnhemp @ 37.5 kg ha-1 seed rate, green manuring with sunnhemp @ 25 kg ha-1 seed rate followed by intercropping) and two nutrient levels as sub sub plots (75% RDF + NPK biofertilizers and 100% RDF). The results showed that in the plant and ratoon crop significantly highest earthworm population was observed with green manuring with sunnhemp @ 25 kg ha-1 seed rate followed by intercropping and was found significantly superior to control treatment. Organic sources can improve both the physicochemical and biological properties of the soil under these conditions, which cousld improve soil ecosystem services and thus increasing the earthworm population.

Soil ecosystem services valuation in a priority terrestrial region for biodiversity conservation in Mexico, from ecological economics and the local community perspective

Soils, often perceived as merely the surface layer of Earth, play a crucial role as the foundation for terrestrial life and are deeply integrated into the worldviews, livelihoods and cultural practices of communities in Mexico. Mexican soils and the ecosystem services that provide are essential for food security and ecological resilience, especially amidst environmental challenges like climate change, desertification and biodiversity loss. Their conservation, restoration and sustainable management are essential to maintain the country's natural environment and to ensure the integral wellbeing of its inhabitants. This study evaluates the ecosystem services provided by soils in a priority area for biodiversity conservation in Mexico, adopting an approach that merges ecological economics perspectives with local community views. By understanding how residents of this region value their soils, this research highlights the ecological and economical significance of soils and their intrinsic cultural and social value within communities that have coexisted with these ecosystems for generations.

Assessing organic carbon sequestration in soil aggregates for building high quality carbon stocks in improved grazing lands

Soil aggregation is critical for increasing soil organic carbon (SOC) sequestration and ecosystem services in improved grazing lands (IGLs). Evaluating soil aggregation under various IGL practices can better inform SOC accumulation potential. Assessing SOC within soil aggregates and examining quality indicators can provide additional insights for building stable SOC stocks. The objective of this study was to analyze soil aggregation and aggregate-SOC content and its quality parameters to evaluate the long-term (>50 years) impacts of different grazing and fertilization practices on SOC-sequestration in comparison to a minimally managed native pine forestry site (FS). Experimental treatments in IGLs included two grazing pressures of high (HGP) and low (LGP), and two nitrogen (N) fertilization of either only organic-N (oN) through a legume rotation or only inorganic fertilized (iN). Soil cores collected from a 0–60 cm soil profiles were separated by depth, which were further separated into aggregate fractions through dry sieving. Individual aggregate fractions were analyzed for SOC content, CN ratio (CNR) and fungal to bacterial ratio (FBR) to evaluate the quantity and quality of SOC. Results indicated contrasting trends between soil aggregation and SOC in response to grazing and N management. Sand-free Mean Weight Diameter (sfMWD, mm 50 g–1) was higher in HGiN (1.03 mm), HGoN (1.00 mm), and in FS (0.95 mm) compared to LGoN (0.76 mm) and LGiN (0.65 mm). Whereas aggregate-SOC (g kg–1) and stocks (Mg ha–1) were significantly higher in LGiN (7.64 and 40.3, respectively) and LGoN (5.06 and 39.3, respectively), than HGoN (3.77 and 20.8, respectively) and HGiN (5.63 and 26.7, respectively), but comparable to FS (4.61 and 44.2, respectively). Higher SOC in LGP was largely due to higher independent-MOC (mineral occluded carbon in silt+clay). Higher soil aggregation under HGP did not increase SOC, confirming the potential loss due to overgrazing effects. Comparison of the summed-index based on several SOC quality indicators, including CNR and FBR, ranked FS highest, followed by LGoN and LGiN. Although LGiN accumulated the highest SOC stocks, a combined quantitative and qualitative assessment of SOC sequestration revealed that low intensity grazing with reduced N input and integration of legumes was a superior IGLs practice. These findings highlight the importance of incorporating aggregate-SOC quality parameters to evaluate SOC-sequestration potential.

Soil Ecosystem Services in Urban Parks as a Basis for Better Urban Planning: The Case of Mexico City

Until now, the contribution of soils in urban spaces has been underestimated and, as a result, the services they provide have been severely undervalued in urban planning. This article aims to address this issue through a study of Chapultepec Park in Mexico City. We provide two methodological proposals for the analysis of soil ecosystem services characterized by the interaction of natural and anthropic processes: the morpho-pedological landscapes (MpL), in which we quantify soil carbon sequestration (SOC Mg ha−1) and the comparison of two methods for the analysis of hydraulic conductivity: Pedotransfer functions (PTF) and direct measurement with a double ring infiltrometer. Among the 12 MpL, we found the highest SOC content in slopes with mixed tree vegetation and Phaeozem soils. However, SOC retention decreased by 40%–50% due to sealing surfaces. For infiltration measures, despite the diversity of soils and vegetation, direct measurements values are highly homogeneous, while values calculated using PTFs better reflect the morphopedological landscape heterogeneity. In all the MpLs, the hydraulic conductivity was higher than the maximum rainfall intensity report, indicating that the soils in Chapultepec Park, despite the differences in soils and intensity of use, provide the ecosystem service of infiltration. These results would allow the establishment of a baseline for monitoring these services and provide information to decision makers and urban planners seeking to reduce the construction of gray infrastructure that seals soils and reduces their capacity to provide these ecosystem services.

Soil biodiversity and microbial antagonism for suppression of plant-parasitic nematodes

Abstract Plant parasitic nematodes (PPN) cause significant economic losses in agriculture and the use of nematicides is the most common management practice applied today. However, due to the impact of such chemicals, more sustainable methods are needed. Current trends consider the exploitation of indigenous soil microbial communities. In this review we discuss some concepts required for the conservation and management of soil microorganisms, considered as a fundamental natural resource. Co-evolution and co-speciation are basic evolutionary processes of soil taxa involved in soil ecosystem services such as nematode regulation. The microorganisms showing a host-parasite co-evolution hold potential for the insurgence or re-construction of a natural equilibrium in soil, aiming at nematode regulation. The impact on soil microbial diversity of farming intensification and PPN management through nematicides is also discussed. Some examples of soil microbial resources and their impact including antagonists like nematophagous fungi (NF), aquatic parasites and bacteria are also briefly reviewed.

A Study on Future Population Dynamics of Indigenous Earthworm Species in Golaghat District of Assam, India

This study presents a pioneering exploration into the population dynamics of indigenous earthworm species in the Golaghat district of Assam, India, through the lens of mathematical modeling. Recognizing the integral role of earthworms in enhancing soil productivity and ecosystem health, we embarked on a detailed longitudinal analysis spanning from 2018 to 2023 to assess their population trends across different seasons and subdivisions within the district. Utilizing the principles of Mathematical Biology, we employed the Malthus Growth model and the Logistic Growth model to estimate future population trajectories of earthworm species, integrating biological insights with mathematical rigor. Our methodology, combining extensive field data collection with sophisticated mathematical modeling, provides a replicable framework for similar ecological studies. This study contributes to the growing field of Mathematical Biology, offering a novel approach to understanding the complex interactions within ecosystems and the impact of environmental changes on key species. The outcomes offer valuable insights into sustainable agricultural practices and biodiversity conservation in tropical and subtropical regions, emphasizing the critical role of indigenous earthworm species in maintaining soil health and ecosystem services. Our findings reveal significant seasonal variations and highlight the resilience of these species in the face of ecological changes. The models suggest distinct population growth patterns, with the Logistic model providing a more realistic projection considering environmental constraints and resource availability. The bifurcation diagram is drawn for the Logistic map that presents the phenomena inside the chaotic region.

In search of a sound scientific basis for quantification of soil precompression stress

AbstractSoil compaction is a serious threat to soil functions and ecosystem services. Persistent soil deformation takes place when mechanical stress exceeds soil strength. Risk assessment models typically assume soil to be elastic to a precompression stress level and plastic above this threshold. Currently used procedures for estimating soil precompression stress imply applied stress in a logarithmic form that has been criticized. We performed uniaxial, confined compression tests on 117 soil samples with a well‐defined stress history. Strain and stress were recorded at 200 levels of stress in the range of 0–1 MPa. Soil compressibility was calculated as incremental strain per incremental stress, using stress in arithmetic scale. For a given sample, a local minimum in compressibility appeared close to the preload applied to the sample prior to the compression test. This yield stress is suggested as an expression of soil precompression stress. Not all samples displayed a yield stress. Primarily soil exposed to a high preload did not exhibit a clear stress level with change in compressibility. This indicates that a physically based stress level pointing out a transition to plastic conditions will not exist for all soils. Our observation calls for new concepts in risk assessment. Tests with interpolation between a limited number of data points indicate that the yield stress—if existing—may be detected from classical compression data.

Potential of biochar to restoration of microbial biomass and enzymatic activity in a highly degraded semiarid soil

Biochar is an effective material for enhancing soil ecosystem services. However, the specific impacts of biochar on microbial indicators, particularly in degraded soils, remain poorly understood. This study aimed to evaluate the effects of biochar produced from cashew residues and sewage sludge, in a highly degraded soil, on microbial indicators. We analyzed soil chemical composition and microbial biomass C and N, enzyme activity, and stoichiometry. Cashew biochar increased soil respiration, indicating a higher availability of C to microorganisms compared to sewage sludge biochar and a better adaptation of soil microbial communities to C-rich organic material obtained from a native plant. Although the biochar differentially impacted microbial biomass C, both significantly increased N in the microbial biomass. Arylsulphatase activity did not respond to biochar application, while β-glucosidase, urease, and phosphatases showed significant changes with biochar treatments. Importantly, stoichiometry and vector analysis revealed that both types of biochar increased P limitation for soil microbes. Conversely, both biochar alleviated C and N limitations for the soil microbes. Thus, biochar applications in highly degraded soils should be supplemented with external P sources to maintain soil functions, mainly for cashew residues. Our results provide evidence that biochar can restore soil biological properties and enhance the availability of C and N to microorganisms. These findings have significant implications for restoration practices in degraded lands of semiarid regions.

New insights into the prediction for the potential of soil organic carbon accumulation: From the perspective of non-equilibrium statistical mechanics

The accumulation of soil organic carbon (SOC) is significant for soil health and ecosystem services. Numerous studies have assessed the dynamic changes of SOC by considering the microbial system as an equilibrium system. However, they failed to reveal the complexity of the SOC accumulation/loss process, as the microbial system is a non-equilibrium system affected by stochastic fluctuations from the external environment. This study is the first to explore the complex non-equilibrium relationship between microbial carbon use efficiency (CUE) and SOC by using potential landscape and flux in non-equilibrium statistical mechanics. Nitrogen (N) was identified as the most critical environmental factor influencing CUE on a global scale, with the transition between the carbon loss state and the carbon sequestration state observed along N gradients. Random perturbations of other environmental factors could also trigger transition. Non-equilibrium thermodynamic quantities indicated that carbon sequestration had the potential to be achieved when N = 0.5 g/kg, where active soil management measures should be taken. Furthermore, the non-equilibrium relationship between CUE and SOC was clarified through potential energy analysis, where the average deviation between predictions and actual observations of SOC is about 1.9792 g/kg. This study provides an effective framework for predicting SOC accumulation.

Impacts of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on maize yields, nutrient use efficiency, and soil nutrient balance: Insights from a long-term diverse NPK omission experiment in the North China Plain

Context or problemSoil nutrient deficiency is one of the significant challenges in grain production, particularly nitrogen (N), phosphorus (P), and potassium (K). These deficiencies not only reduce crop yields but also cause associated environmental issues, such as soil structure deterioration and ecosystem services diminution. ObjectivesThis research aimed to investigate the long-term effects of NPK fertilizers on soil nutrient properties and maize phenology, further on the grain yield, and to evaluate the nutrient use efficiency and soil nutrient balance under different fertilization managements. MethodsA long-term field experiment was initiated in 1990 in a summer maize field in the North China Plain, including five fertilizer treatments: CK (control), NP, NK, PK, and NPK. The soil nutrient properties, maize yields, crop nutrient uptake amount, nutrient recovery efficiency (NRE), nutrient harvest index (NHI), and soil nutrient balance were annually evaluated from 2005 to 2022. ResultsSignificant improvements in maize yields were found under NPK (9081 kg ha−1), NP (6426 kg ha−1), and PK (2668 kg ha−1) compared with CK (1809 kg ha−1) and NK (1656 kg ha−1). The yield increase was mainly attributed to: (1) enhancing in soil nutrient properties, such as soil organic carbon, soil total N (TN), available N (AN), total P (TP), available P (AP), and available K (AK), and (2) the shortened vegetative period, leading to greater sunshine hours (SH) and accumulative growing degree days (GDD) during the reproductive period. Furthermore, a random forest analysis quantified their importance to grain yield, showing that the edaphic factors (mainly SOC, TN, AK, AN, TP, AP, C:N, and N:P) explained a much greater proportion of yield variation compared with phenological factors (mainly GDD during tasseling and physiological maturity stages, and SH during tasseling stage). Additionally, the significantly higher response ratio of both N and P to NRE and NHI implied that N and P fertilizers having a more pronounced impact on improving nutrient use efficiency than K fertilizer. In terms of soil nutrient balance, a most relative soil nutrient balance was detected under NPK treatment, avoiding either substantial nutrient depletion or accumulation under any nutrient deficiency conditions. ConclusionsSoil deficiencies in N and P had more severe impacts on maize yields and nutrient use efficiency compared with K deficiency. Additionally, a balanced NPK fertilizer regime effectively managed soil nutrient balance. Implications or significanceThese findings elucidate the roles of N, P, and K fertilizers in maize production and soil nutrient conditions from a long-term field experiment, which could provide valuable insights for optimizing fertilization management strategies.